A hike in the price of bus tickets has triggered four days of protests in some of the largest cities in Brazil.

In a country not accustomed to too many public demonstrations, the response of the authorities has been severe, with police tear-gassing and shooting rubber bullets at protesters. In Sao Paulo, 100 people have been hurt and 250 arrested on Wednesday alone, as reported by local newspaper Jornal do Dia. Rio de Janeiro witnessed damage to public property, including bus stops, garbage bins and official buildings, by vandalizing protesters, newspaper O Globo reports.

The ticket price increase coincided with weakness in the Brazilian stock market and currency and a decline in the popularity of President Dilma Rousseff.

Public transportation in Brazil is not cheap, particularly for the masses of working poor who earn minimum wage. A single-ride ticket in Sao Paulo allows a maximum of four trips in three hours and now costs 3.20 reais ($1.50), up from a previous price of 3 reais. In a city in which many people work six days per week, two trips per day can push the cost of public transport to more than 200 reais a month ($93), whereas the monthly minimum wage is 678 reais ($317).

However, in some cities, the protests drew results: For example, in the northeastern coastal city of Natal, local authorities reduced the price of bus tickets to their original cost.

The huge metropolis of Sao Paulo witnessed the most violent of demonstrations on Wednesday night, with more than 5,000 protesters taking to the streets and the police responding with force -- six journalists from daily newspaper Folha de Sao Paulo were hurt in the melee.